(!)Warning, it work in every version, (probably but not 100% sure like 99.9% sure) But i put it in 1.19.4 pre realse2 because i'm playing on it but it work in 1.8.9)

So, put a server with an icon (like hypixel) put a random ip (like "jzufigdqdyusfgqyugfb.net") and when you come back and even REFRESH it have the icon (here hypixel) of the server that where here before.

Warning i'm not promoting hypixel its just better for the example

How to Reproduce?

1) Add a server, in the ip put "hypixel.net"

2) Save it

3) Put "siufhdqsioh.net" in the ip (example)

4) Save it

5) Even if you refresh it would still have the icon of Hypixel.

It's just a bug that i see in every version and i don't think it's new so yep.